/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.rocketmq.client.java.misc;

import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * Linked iterator is a simple iterator class that allows you to iterate over a linked list.
 *
 * @param <T> the type of the elements to be iterated over.
 */
public class LinkedIterator<T extends LinkedElement<T>> implements Iterator<T> {
    private T cursor;

    public LinkedIterator(T cursor) {
        this.cursor = cursor;
    }

    /**
     * @see Iterator#hasNext()
     */
    @Override
    public boolean hasNext() {
        return null != cursor;
    }

    /**
     * @see Iterator#next()
     */
    @Override
    public T next() {
        if (null == cursor) {
            throw new NoSuchElementException();
        }
        T t = cursor;
        cursor = cursor.getNext();
        return t;
    }
}
